Effects of anteriorly-loaded treadmill walking on dynamic gait stability in young adults

BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η² = 0.114) and liftoff (p = 0.122, η² = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η² = 0.648) and liftoff (p < 0.001, η² = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η² = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion.     

滋肾育胎丸加减方预防ACA阳性者不良妊娠结局的效果及机制研究＊

目的 探讨滋肾育胎丸加减方预防抗磷脂抗体（ACA）阳性者不良妊娠结局的效果及机制研究。方法 选取2016年2月至2019年2月我院收治的89例ACA阳性，先兆性流产或有习惯性流产（RSA）史患者，将采用西医治疗的40例作为对照组，将采用西医联合滋肾育胎丸加减方治疗的49例作为观察组，比较两组中医证候疗效、中医证候积分、ACA-IgA、ACA-IgM、ACA-IgG、凝血指标［血小板聚集功能（PAF）、活化蛋白C（PC）、抗凝血酶（AT）、纤溶酶原激活抑制物-1（PAI-1）］、Th1/Th2细胞因子［干扰素γ（IFN-γ）、白介素-2（IL-2）、白介素-4（IL-4）、白介素-10（IL-10）］、妊娠结局、安全性。结果 治疗2周后检测ACA，观察组2例未降低，对照组11例未降低，观察组未降低患者占比低于对照组（P<0.05）；观察组总有效率100.00%高于对照组85.00%（P<0.05）；观察组治疗4周、7周后中医证候积分低于对照组（P<0.05）；观察组治疗4周、7周后ACA-IgA、ACA-IgM、ACA-IgG低于对照组（P<0.05）；观察组治疗4周、7周后PAF、PAI-1低于对照组，PC、AT高于对照组（P<0.05）；观察组治疗4周、7周后IFN-γ、IL-2低于对照组，IL-4、IL-10高于对照组（P<0.05）；观察组活产率95.92%高于对照组80.00%（P<0.05）；组间不良反应总发生率比较，差异无统计学意义（P>0.05）。结论 动态监测ACA对滋肾育胎丸加减方精准应用具有指导意义，指导滋肾育胎丸加减方通过调理脏腑、气血、经络功能，改善先兆性流产或有RSA史患者临床症状及凝血因子指标，降低ACA水平，并可改善患者免疫耐受功能，提高胎儿活产率，且安全性高。     

Role of the newly designed Ankle Foot Orthosis on balance related parametersin drop foot post stroke patients

BackgroundPassive and hybrid passive ankle foot orthoses (AFOs) are often prescribed in post stroke drop foot; however, the effects of these AFOs on balance related parameters in these patients seem unclear. Accordingly, the aim of current study was to evaluate the role of the newly designed hybrid passive and Posterior Leaf Spring (PLS) AFOs on balance related parameters including: self-reported balance confidence (ABC), Timed Up and Go Test (TUG) and Berg Balance Scale (BBS) in post stroke drop foot patients.MethodsFifteen post stroke drop foot patients were recruited in current study. Then, ABC, TUG and BBS were assessed with newly designed AFO and PLS AFO.ResultsThe results of this study were shown a significant improvement in ABC, TUG and BBS scores with the newly designed AFO than PLS AFO (p < 0.05).ConclusionThis study suggested that the newly designed AFO was improved the balance related parameters than PLS AFO.     

Dynamic functional connectivity of the EEG in relation to outcome of postanoxic coma

ObjectiveEarly EEG contains reliable information for outcome prediction of comatose patients after cardiac arrest. We introduce dynamic functional connectivity measures and estimate additional predictive values.MethodsWe performed a prospective multicenter cohort study on continuous EEG for outcome prediction of comatose patients after cardiac arrest. We calculated Link Rates (LR) and Link Durations (LD) in the α, δ, and θ band, based on similarity of instantaneous frequencies in five-minute EEG epochs, hourly, during 3 days after cardiac arrest. We studied associations of LR and LD with good (Cerebral Performance Category (CPC) 1–2) or poor outcome (CPC 3–5) with univariate analyses. With random forest classification, we established EEG-based predictive models. We used receiver operating characteristics to estimate additional values of dynamic connectivity measures for outcome prediction.ResultsOf 683 patients, 369 (54%) had poor outcome. Patients with poor outcome had significantly lower LR and longer LD, with largest differences 12 h after cardiac arrest (LR_θ 1.87 vs. 1.95 Hz and LD_α 91 vs. 82 ms). Adding these measures to a model with classical EEG features increased sensitivity for reliable prediction of poor outcome from 34% to 38% at 12 h after cardiac arrest.ConclusionPoor outcome is associated with lower dynamics of connectivity after cardiac arrest.SignificanceDynamic functional connectivity analysis may improve EEG based outcome prediction.     

A novel extraoral registration method for a dynamic navigation system guiding zygomatic implant placement in patients with maxillectomy defects

Zygomatic implants (ZIs) are used for the oral rehabilitation of patients with maxillectomy defects as an alternative to extensive bone grafting surgeries. New technologies such as computer-assisted navigation systems can improve the accuracy and safety of ZI placement. The intraoral anchorage of fiducial markers necessary for navigation registration is not possible in the case of a severe maxillary defect and lack of residual bone. This technical note presents a novel extraoral registration method for a dynamic navigation system guiding ZI placement in patients with maxillectomy defects. Titanium microscrews were inserted in the mastoid process, supraorbital ridge, and posterior zygomatic arch as registration markers. The mean fiducial registration error (FRE) was 0.53 ± 0.20 and the deviations between the planned and placed ZIs were 1.56 ± 0.54 mm (entry point), 1.87 ± 0.63 mm (exit point), and 2.52 ± 0.84° (angulation). The study results indicate that the placement of fiducial markers at extraoral sites can be used as a registration technique to overcome anatomical limitations in patients after maxillectomy, with a clinically acceptable registration accuracy.     

Reliability and criterion validity of two-dimensional movement assessments in those with patellofemoral pain

ObjectivesDetermine criterion validity and intra/inter-rater reliability of 2-dimensional (2D) knee frontal plane projection angle (kFPPA), hip frontal plane projection angle (hFPPA), and dynamic valgus index (DVI) during forward step-downs in those with patellofemoral pain (PFP).DesignCross-sectional.SettingUniversity research laboratory.Participants39 participants with PFP (34.18 ± 7.41years, 170± .1 cm, 81.03 ± 19.36 kg, duration of pain: 68.67 ± 85.08months, anterior knee pain scale: 80.49 ± 7.87, visual analog scale:2.08 ± 2.02)Main outcome measuresAverage 3D hip and knee sagittal, frontal, and transverse joint angles and 2D kFPPA, hFPPA, and DVI at maximum knee flexion were variables of interest. 3D DVI was calculated as the sum of hip and knee frontal and transverse angles. 2D kFPPA, hFPPA, and DVI were calculated by two raters independently on two occasions.ResultsIntra- and inter-rater reliability of all 2D angles were excellent. kFPPA was moderately correlated to 3D knee transverse angles. hFPPA was moderately correlated to 3D hip frontal and transverse angles and largely correlated to 3D DVI. 2D DVI was moderately correlated to hip transverse angles.ConclusionkFPPA, hFPPA, and DVI are reliable. hFPPA may be reflective of 3D hip and knee frontal and transverse motion during forward step-downs in those with PFP.     

Dose calculation of dynamic trajectory radiotherapy using Monte Carlo

Purpose

Using volumetric modulated arc therapy (VMAT) delivery technique gantry position, multi-leaf collimator (MLC) as well as dose rate change dynamically during the application. However, additional components can be dynamically altered throughout the dose delivery such as the collimator or the couch. Thus, the degrees of freedom increase allowing almost arbitrary dynamic trajectories for the beam. While the dose delivery of such dynamic trajectories for linear accelerators is technically possible, there is currently no dose calculation and validation tool available. Thus, the aim of this work is to develop a dose calculation and verification tool for dynamic trajectories using Monte Carlo (MC) methods.